Automatic telephone switch



Aug. 22, 1933. c. P. SMITH ET AL AUTOMATIC TELEPHONE SWITCH Fild July28, 1932 [g w 5% w Tfi 1?? 2 Sheets-Sheet 1 FIG. I

INVENTORS CHARLES P. SMITH GEOFFREY N WTON ATTORNEY I Aug. 22, 1933. Q RSMITH Er AL 1,923,282

AUTOMAT IC TELEPHONE SWITCH Filed July 28, 1932 2 Sheets-Sheet 2INVENTORS CHARLES F. SMITH CEOF EY NEWTON M ATTORNEY Patented Aug. 22,1933 PATENT OFFICE I 1,923,282 7 AUTOMATIC TELEPHONE SWITCH Charles P.Smith and Geoffrey Newton, Aldwych,

London, England, assignors to International Standard ElectricCorporation, New York,

N. Y., a Corporation of Delaware Application July .28, 1932, Serial No.625,324,

and in Great Britain November 27, 1931 20 Claims.

This invention relates to switching mechanisms more particularly, thoughnot exclusively, for use as non-numerical or numerical selectors inautomatic or semi-automatic telephone exchange systerns.

The object of the present invention is to provide a switching mechanismwhich is cheap and simple in operation and which gives much quickerswitching operation than the switches of the general type which havebeen previously proposed.

The switch mechanism according to the invention is particularly adaptedfor use in common control or marking systems of automatic or semi.-automatic telephony.

One feature of the invention comprises a switch mechanism adapted tomake connection between any one of a, plurality of incoming lines'andany one of a plurality of outgoing lines, in which each incoming line isconnected to a switching unit and each outgoing line is connected to acontact set individualto each of said incoming lines and in whichcontrol means are provided to select and move all the contactsets'connected to one outgoing line to an off-normal position, andfurther means are provided for moving each switching unit to anoff-normal position, connection being obtained between a contact set anda switching unit when both have been moved off-normal.

According to another feature of the invention the contact bank of aswitch mechanism comprises a number of groups of contacts each groupincluding a contact individual to each outgoing line, one of said groupsbeing used for selecting purposes only, and the other groups being usedfor connecting purposes only.

The above and other features of the invention will be better understoodfrom the following description of one embodiment thereof shown in theaccompanying diagrammatic drawings in which:

Fig. 1 is a cross-sectional plan view of. the switch showing oneoutgoing bank multiple,

Fig. 2 is a partial view of one side of the switch mechanism,

Fig. 3 is a view of one end of the switch mech anism showing the mainoperating mechanism.

Fig. 4 is a circuit arrangement for the switch when used as a secondgroup selector in' a system having feed in the first stage.

The switch is rectangular in horizontal cross section, the two longersides comprising flat contact banks on each of which each outgoing lineappears five times so that each line makes ten appearances in the bank.Each line multiple is 55 formed by a bundle of 30'bare wires suitablyinsulated from one another, giving sets of 10, a, b and c wires. Themultiple enters from one end of the bank at which three connecting tagsare provided and the Wires are turned off at right angles at intervalsin groups of three (a, b and 0 wires) as shown in Fig. 1, the tips ofthese wires forming the multiples as shown. In addition two test ormarking wires 11, 12 connected to wiring tags 2,3 at the terminal end ofthe switch pass right through the bank to commutators 28 at the oppositeend of the switch. The complete bank comprises a number (250 forinstance) of outgoing line multiples assembled one above the other inhorizontal rows. The multiples extend-- ing to the opposite faces. ofthe switch may be kept separate, and used for different groups ofoutlets if desired.

It will be appreciate that each multiple face of the switch consists offive vertical groups of sets of contacts, each set being individual toone outgoing line. Associated with each vertical group is a verticalswitching unit formed by three metal angie bars I joined by insulatingcross members 16. The switching units are pivoted top and bottom tomembers 20 and 36 respectively. The member 29 is the pivoted armature ofan electromagnet 21 mounted on the top of the switch frame, while themember 36 forms part of a two armed lever pivoted to the bottom of theswitch framework and carrying a counterweight V 37 which ensures thatthe magnet 21 will be able to move the switching unit. It will be notedthat the magnet 21 and the lever 36' are mounted in such a way that theswitching unit 1, 16 associ ated therewith will move towards the hatcontact bank but diagonally thereto as indicated by the arrow in Fig. 1.The purposes of this will be explained later. The commutators 23 areeach mounted adjacent a'parallel continuous conducting strip Eachcommutator and its associated conducting strip are adapted to be wipedover by long flexible wiper members 4, 4 bridging the commutator andfeeder bars. The wipers are mounted on a horizontal bar 2'7 fixed toslide member 25 journalled for up and down movement on a vertical guiderod 35. V The member 25 carries'a half-nut 26 while the guide rod 35 ismounted between two levers 31 pivoted on the spindle 34. Thecontinuation of the spindle 34 carries the armature 32 of anelectromagnet 33 which when operated tends torotate the levers 31against a spring 30 to engage the half-nut 26 with a screw shaft 24which is adapted to be driven by an electric motor 5 The ends of thebare wire multiplesof each outgoing line at each face of the bank arethreaded through insulated slots in horizontal metal bars 13. These barsare normally held to the left in Figure l by the spring tension of themultiple wires and their left hand ends are positioned for engagementwith operating members 14 on the horizontal bar 2'? carrying the wipers4. 'Each of the switching units 1, 16 is connected to an incoming lineby means of three spiral wires (not shown) connected to wiring tags onthe with the shaft. The bar 27 and wipers 4 are then raised fromtheirnorinal position at the bottom of the switch and test the outgoinglines by means of the commutators 28. When an idle or wanted line isreached (this may be an idle line in a par ticular group) theelectro-magnet 33 is deene gized and the half-nut 26 is withdrawn fromthe shaft by means of the spring 39. The bar 27 is thereby stoppedopposite the ends of the bars 13 in which the multiple wires of theparticular out-- let selected are engaged, and is brought intoengagement with these bars to force them to the right, Fig. 1. Thisaction displaces the ends of the contact wires of the selected outlet tothe right of their normal position, in a position in which they aresituated to the right of the correspond-- ing angles 1 of the associatedswitching unit. One of these switching units will have been previouslyselected and its electro-magnet2l is not operated. he switching unit 1,16 is now moved towards the multiple bank in a diagonal direction aspreviously described. The members 1 engage the corresponding wires ofthe displaced multiple ire and during their further movement rub overthe wires in a vertical and horizontal direction, at the same timefurther displacing said wires towards the right. The magnet 33 is thenoperated to withdraw the bar 27 from engagement with the bars 13 so thatthe bars 13 and the wire multiple of the selected outlet, with theexception of the three wires engaged by the switching unit return tonormal position. v In addition the half-nut 26 engages the shaft 24which in the meantime has been stopped and rotated in the oppositedirection so that the bar 27 is returned to normal position. If theswitch is used as a non-homing simple hunting switch it would remainwith a pair of bars 13 pushed to the right in Fig. 1, by the horizontalbar 2'7 when not in use. When used as a simple hunting switch of thehoming type it can be arranged to home to either end of the bank asrequired, that is to say, if it started from the bottom it could be madeafter selection to home to the top and when next taken into use wouldoperate'in reversed direction. Instead of having an individual motordrive for each switch, a number of switches inan exchange could bearranged for operation by means of mechanical gearing driven from asingle motor. In this case a simple bevel gear drive arranged forreversal could be provided.

Mechanically-operated contact assemblies are provided as required. Forinstance in Fig. 2 a set of contact springs 39 is shown on the magnet21, adapted to be operated by an extension of its "arrangement shown inFig. 4 for the switch when used as a second group selector in a forwardhold system. It is to be understood that this circuit is by way. ofexample only, and that the switch can also be used as a call finder or afinal selector or for any other suitable purpose.

On a call incoming to the switch earth is connected over wire 'I',contact cml, normally closed contacts on1 of the selector (which may befor example the'normal contacts indicated at 38 in Fig. 3), back contactb1, wiper pml and its normal contact to protected battery. A loop isextended forward on the positive and negative wires and relay A isoperated over back contacts C1122,

C1013. Relay A operates relay B in known fashion and the motor startcircuits are closed at be and 225. When the next digit is receivedmagnet PM of the marker switch is impulsed; earth, a1, b3, winding ofrelay C, e1, winding of PM, battery. Relay C remains operated throughoutdialling of this digit in known manner. On the first in1- pulse thewipers of the marker switch step oil normal and a circuit is closed formagnet TM (which corresponds to magnet 33 of Fig. 3); earth, pm2, b2,101, ml, g3, winding of TM, battery. Wiper 4 of the switch hunts for itsmarked contact as described in known manner. When this contact isreached relay M is operated; earth b7, e4, pm3, marking conductor, wiper4, c6, winding of M, battery. When relay C falls off at the end of thedigit and relay M has been operated relay E pulls up; battery, windingof relay E, 01, e2, m1, p1, b2,'pm2, earth. The operation ofrelay Eopens at e4 the circuit for circuit of magnet TM which hunts via wiper 4for an idle line in the selected group. When an idle line is found relayP operates; earth, windings of P, 95, e5, Wiper 4 to idle batterypotential on the outgoing T wire. Relay P busies theselected line byshort circuiting its high resistance upper winding at p2 and at plcloses the circuit for relay H which operates and locks up over 724-,I26 toearth and at contacts hl, I22 connects battery to the windings ofthe relays CM, which correspond to the magnets 21, Fig. 2. It has beenassumed that the first selector stage is the battery feeding stage andearth is present on the wire H so that relay CM now operates and locksat cm l, disconnecting the positive, negative and T wires so that relaysA releases followed by the other relays. Switch PM then homes via itsinterrupter contacts, b2, pm2. The release of'relay' B closes a circuitfor relay N over offnormal contacts on2 and b7. The operation of Nmaintains the field excitation of the selected.

relay M which falls back and at m1 again closes the home where thecontacts 0212 are opened and contacts onl closed. If no idle 'line hasbeen found in the selected group relay M would have re-operated onthelast line via 96, wiper 4,0115. lead, c4, b7, operated relay Genergises via e2, mi, :01, b2, pm2, earth. Relay G locks via g2, c3, b6,conearth. With relays E and M both nects up busy tone at 91, operatesrelay N to reverse the drive at 94 and at g3 opens the circuit of magnetTM which is, however, operated via n1 so that the switch homes. When theon2 con tacts open. relay N releases and releases magnet TM, the normalcircuit for which is open at g3 and also stops the motor since contacts97 are open. When the subscriber hangs up release takes place due torelay A releasing.

What we claim is:

l. A switch mechanism comprising a bank of movable contact sets arrangedin a plurality of rows, a plurality of movable switching units eachadapted to cooperate with the contact sets in a plurality of rows, meansfor moving the contact sets of a selected row into the path of saidswitching units and means for moving a selected switchng unit to connectwith a contact set in said selected row.

2. A switch mechanism comprising in combination a main contact bank, anauxiliary contact bank, a plurality of switching units for cooperati onwith said main contact control switch unit for cooperation with saidaux' iary contact .a means for marking contacts in said auxim by contactbank, means for driving said control switch unit over said auxiliarycontact bank under control of said. marking means to select particularset of contacts in said main contact l. and means for operating one ofsaid switchin units to connect with said selected set of contacts.

3. A switch mechanism adapted to make con-- nection between any one of aplurality of incoming and outgoing lines in which each incoming line isconnected to a movable switching unit and each outgoing line isconnected to a contact set individual to each of said incoming lines andin which control means are provided to'select to all the contact setsconnected to one outgoing line to an off-normal position and furthermeans are provided for moving each switching unit to an off-normalposition, connection being obtained between a contact set and aswitching unit when both have been moved offnormal.

4. A switch mechanism comprising in combination, a flat contact bankhaving a number of adiacent rows of contacts in which each outgoing lineis connected to a number of contacts in the same row, a number ofswitching units each of a length. sufficient to span said adjacent rowsof contacts and arranged at right angles to said rows and adiacent to asingle set of contacts associated with each outgoing line, control meansfor selecting an outgoing line in said bank, further means associatedwith each .of said contacts in a row and adapted to move all themultiple contact sets of said row out of alinernent with thecorresponding contact sets of other outgoing lines in the remaining rowsunder control of said control means. and for moving a selected one ofsaid switching units to engage a particular set of contacts in the rowwhich has been moved out of alignment and so complete a connectionbetween an incoming line connected to said switching unit and theoutgoing line connected to said set of contacts.

5. A switch mechanism as claimed in claim 4 characterized in this thatsaid control means comprises a test wiper adapted to be moved over acommutator having a plurality of contacts each corresponding to one ofsaid rows of contacts in the switch bank and each connected to a testwire associated with the outgoing line connected to that row ofcontacts.

6. A switch mechanism as claimed in claim 4 characterized in this thateach outgoing line multiple comprises groups of wires in the same orsubstantially the same plane, said wires being arranged substantially atright angles to the face of the contact bank which is formed by the endsof said wires.

7. A switch mechanism as claimed in claim 4 characterized in this thateach outgoing line multiple comprises groups of wires and that saidwires forming the contacts of an outgoing line pass through slots in abar arranged in the plane of, but at right angles to said wires, and inwhich a device associated with said control means is adapted to bepositioned opposite the bar associated with the wires of an outgoingline and to be shifted to move said bar so that the wires are moved outof alignment with the wires of the other outgoing lines.

8. A switch mechanism as claimed in claim 4 characterized in this thatthe wires forming the contacts of outgoing lines pass through slots in aplurality of bars and that each switching unit comprises a plurality ofrigidly connected and insulated parallel contact strips, arranged to bemoved bodily towards the associated portion of the contact bank in sucha manner that said bars will only engage contact wires which have beenforced out of normal alignment.

9. A switch mechanism as claimed in claim 4, characterized in this thatthe wires forming the contacts of outgoing lines pass through slots in aplurality of bars and that each switching unit is 110 arranged to bemoved in such a manner as to force the contact wires with which it makescontact still further out of alignment so that the switching unit whenin use will not interfere with movement of said bars and contact wiresand in which the slots in said bars are of such length as to allow thebar to return to its unoperated position when one or more sets of wirescontrolled thereby are held in said last mentioned position by saidswitching unit.

10. A switch mechanism as claimed in claim 4 characterized in this thatit comprises two oppositely disposed fiat contact banks with each ofline.

12. A switch mechanism as claimed in claim 4, characterized in this thatsets of wires for each outgoing line are multipled and brought out toconnecting tags at one end of a contact bank, and a separate test wirefor each outgoing line is connected to the commutator device associatedwith said control means at the opposite end of said bank.

13. A switch mechanism as claimed in claim 4 characterized in this thata plurality of sets of contact wires and two oppositely disposed contactbanks are provided and that a slotted bar cooperates with the contactwires on each contact bank, and said control means comprises anoperating bar parallel to the planes of said contact sets and adapted tocooperate with the ends of electroznagnet being associated with bothslotted bars of a selected outgoing line whereby the contacts in bothbanks are displaced simultaneously.

14. A switch mechanism as claimed in claim 4, characterized in this thatcontrol means comprises a half-nut adapted to engage ascrew drivingshaft, and in which said half-nut is adapted to be moved out ofengagement with the screw when the operating bar shifts said slottedbars to move the contact sets of a row out of alignment with the contactsets in the remaining rows.

15. A switch mechanism as claimed in claim 4, characterized inthie thatcontrol comprises a driving shaft and that id driving shaft is driven byan electri motor i dividual'to said shaft or by reverse d I from a powershaft which may be common to a number of switches. v v

16. A switch mechanism as claimed in claim l characterized in this thatsaic" control means comprises a half ut adapted to a screw driving shaftand t f-nut is carried by a slide member slida y e guide rod ar rangedparallel to daft but movably supported on the main ranie of the switch,for example on a pair of p' ted levers, v1 such manner that it ismovable towards and away from the driving shaft so that. the half '5 isengaged with and disengaged fr in. the c. -g shaft, an said guide rod tocontrol its movement.-

1'7. A switch mechanism as claimed in claim 4 wherein said control meanscomm'ise a half nut adapted to engage a screw during shaft and whereinthe wires forming the contacts of outgoing lines pass through slots in aplurality of the said guide bar is moved for example under the influenceof a spring to bring the half-nut out of engagement with the drivingshaft, the said operating bar simultaneously engages with and displacesthe slotted contact bar opposite which it stands.

18. A switch mechanism as claimed in claim 4 characterized in this thateach switching unit is vertically arranged and is pivotally mounted atone end on a counterweighted lever and at the oth r end on a levercarrying the armature of an electromagnet individual thereto and adaptedwhen operated to shift the switching unit into engagement with thecontact bank.

19. A switch mechanism as claimed in claim 4 wherein each switch unit isprovided with mounting levers having pivots characterized in this thatthe pivots of said mounting levers are horizontal and at an angle to theplane of the flat contact bank whereby when operated the bars of theswitching unit move towards the bank in an upward and diagonally forwarddirection so as to force the contact wires with which it makescontact'still further out of alignment and to move in contact with saidwires in such a Way as to clean both the contact wires and the bars ofthe switching unit.

